Mr Li repeatedly stabbed Mr McClean before decapitating him

A verdict is due in the trial of a man who beheaded a fellow passenger on an inter-city Greyhound bus in Canada.

A judge will rule whether immigrant Vince Weiguang Li was criminally responsible for the killing.

Mr Li has admitted to murdering Tim McLean but pleaded not guilty to second-degree murder in the attack.

The prosecution and defence agreed that Mr Li, 41, is schizophrenic. The court heard that Mr Li had claimed that God had instructed him to kill Mr McLean.

Psychiatrists testifying for both the prosecution and the defence told the court that Mr Li, a Chinese immigrant, did not know what he was doing when he killed Mr McLean.

Dr Jonathan Rootenberg, for the defence, said Mr Li claimed to hear the voice of God telling him to kill Mr Mclean or risk being killed himself.

"The voice said: 'Do it now... If you don't, he's going to kill you.'"

Dr Stanley Yaren, for the prosecution, said Mr Li was undergoing a major psychotic episode including auditory hallucinations.

Furthermore, Mr Li believed his victim had supernatural powers and would come back to life if he did not cut him apart and spread his body parts around, Dr Yaren said.

Frenzied attack

The attack on 30 July last year took place in front of terrified passengers as the bus travelled through a stretch of Canada's vast prairies.

The court heard the details of the attack in a statement of fact agreed to by the prosecution and defence.

Mr Li, a former church custodian and computer programmer who immigrated to Canada in 2001, stabbed Mr McLean, who was sitting next to him, 50 or 60 times before cutting off his head and removing internal organs.

The attack began without warning. Alerted by screams from the victim, the driver stopped the bus and fled with the other passengers as Mr Li continued his attack.

Police documents said Mr Li appeared to "smell, and then eat parts of Tim McLean's flesh" as they surrounded him in the bus 90km (55 miles) west of Winnipeg.

Body parts were found in plastic bags throughout the bus and the victim's nose and tongue and one his ears were found in Mr Li's pocket, police said.

Mr Li, who had been locked in the bus , was apprehended as he tried to leave by a window.